In England, building work carried out without building regulations approval can be regularised through a retrospective application to the local authority, but the owner may be prosecuted, and councils have powers to serve notices requiring non-compliant work to be altered or removed.

What a regularisation certificate is

The Planning Portal says that where building work is carried out without building regulations approval being sought, the owner may be prosecuted, but a process called regularisation exists to help people who wish to have work approved. A regularisation application is a retrospective application for previously unauthorised works started on or after 11 November 1985. Its purpose is to regularise the works and obtain a certificate of regularisation. The Planning Portal states that exposure, removal or rectification of works may be necessary to establish compliance with the building regulations.

GOV.UK’s building regulations guidance for England adds that regularisation can only be applied for through a local authority building control body, not a private approver. The Planning Portal notes that a certificate is needed even where the work was done before the current owner bought the property, and that the level of detail required varies with the size of the breach, often including a description of the breach and plans if available. The fee varies with the extent of work, and the authority inspects the work to decide whether it complies or what must be done to make it comply. The Planning Portal refers to section 18 of the Building Regulations 2010.

Duties and criminal liability

The Planning Portal explains that where applicable, the client, designer and contractor each have a legal duty under section 2A of the Building Regulations 2010 to comply with the relevant requirements. Ignoring the requirements is a criminal offence that may lead to conviction, an unlimited fine and imprisonment. A local authority may prosecute in the magistrates’ court or the Crown Court under section 35 of the Building Act 1984, and there is no time limit on bringing such a prosecution. Action is usually taken against the person carrying out the work, but if a client has not appointed a designer or contractor, the legal duties fall back on the client.

Compliance notices, stop notices and section 36 notices

According to the Planning Portal, a local authority has a general duty to enforce the building regulations in its area and tries to do so informally wherever possible. It may issue a compliance notice within 12 months of a contravention, requiring non-compliant work to be remedied within a specified time, and a stop notice under section 36C of the Building Act 1984 where the contravention creates a risk of serious harm, meaning specified work cannot be completed until the breach is remedied. Ignoring either is a criminal offence.

Where work is completed without the appropriate building control application, the authority can serve a section 36 notice requiring the owner to pull down or remove the work or alter it to comply. A section 36 notice can be issued up to 10 years after the building work is completed, but not if the work accords with a valid full plans application. If the owner does not comply within 28 days, or a longer agreed period, the authority can remove or alter the work and recover the costs from the owner. Appeals against a section 35 or 36 notice can be made within 21 days to the appropriate court or tribunal.

Private approvers and enforcement

Where a registered building control approver provides the building control service, the Planning Portal says the approver is responsible for checking compliance during the work, usually by advising the client, but approvers have no formal enforcement powers. If the client, designer or contractor refuses to bring non-compliant work into compliance, the approver cancels the initial notice, which may return the work to the local authority. If no other approver takes it on, the local authority takes the building control function and then holds its enforcement powers.

Effect on selling the property

The Planning Portal warns that where the local authority or a registered approver considers building work non-compliant and it is not rectified, no completion or final certificate will be issued, which is likely to come to light in a local land search when the property is sold. GOV.UK likewise says that without approval the owner will not have the certificates of compliance that may be needed on a sale. Anyone who discovers past unauthorised work is advised to contact the local authority about a regularisation certificate.

FAQs

Can a private building control approver issue a regularisation certificate?

GOV.UK says regularisation can only be applied for through a local authority building control body.

Is there a time limit on enforcement?

Prosecution under section 35 of the Building Act 1984 has no time limit, according to the Planning Portal, while a section 36 notice can be issued up to 10 years after completion of the work.

Does this apply in Scotland or Northern Ireland?

The sources describe England. GOV.UK states that Scotland and Northern Ireland have different rules for building regulations.

Bottom line

Work built without building regulations approval is not beyond repair: a regularisation application to the local authority can lead to a certificate, sometimes after opening up or altering the work. Without it, the owner risks notices, prosecution and difficulties on sale. Contact the local authority building control team to discuss the position before applying. This is general information for England, not legal advice.

Sources

This guide draws on the following primary sources, current as of 20 September 2026:

• Planning Portal, “Regularisation”
• Planning Portal, “Failure to comply with the building regulations”
• GOV.UK, “Building regulations approval”

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal or planning advice on any specific property — always confirm requirements directly with your local planning authority.